I am using single phase (water) flow in a pipe. I want to compare friction factor from fluent simulation to that of theoretical equations. How can i determine the friction factor? I think it can be determined with the help of wall shear stress but i cant seem to find any related topic in manuals.

does anybody have any idea? I am looking forward for any help in this regard.

thanks

Friction factor usually a function of the flow reynolds number. Check elementary fluid mechanics textbooks; you should find empirical expressions to determine the same. There are also friction factor charts that you can use to determine the value.